## install ansible
    * yum install ansible -y
    * edit /etc/ansible/ansible.cfg
        host_key_checking = False

     * etid /etc/ansible/hosts
        ```
        echo "[test]
        localhost
        "
        ```

     * copy public key
     ssh-keygen 生成公私秘钥
     ssh-copy-id  root@[主机ip]  拷贝公钥至目标主机

     * test
     ansible test -m ping

